Computer security experts say the recent "SQL Slammer" worm, the worst in more than a year, is evidence that Microsoft's year-old security push is not working.

"Trustworthy Computing is failing," Russ Cooper of TruSecure Corp. said of the Microsoft initiative. "I gave it a 'D-minus' at the beginning of the year, and now I'd give it an 'F."'

Experts: Microsoft security gets an 'F'